Modern onboard avionics networks for serve to provide data transfer between all facets of an aircraft. Avionics systems typically have a variety of systems that provide data to processing components of the aircraft or exchange data among one or more other components of the aircraft. For example, a variety of avionics modules may gather avionics data (e.g., sensors detecting speed, direction, external temperature, control surface positions, and the like) that is routed by the avionics system via an avionics network to one or more aircraft components such as displays, monitoring circuits, processors, and the like. A passive optical network (PON) tree-topology based solution for avionics communication system, such as that disclosed in copending U.S. patent application Ser. No. 12/151,249 may provide the network interconnects between such components.
Large air transport aircraft have on the order of 250 access network devices which are connected to the avionics topology. The cost and complexity of certain components implementing fail-passive operational design in a PON avionics topology may be prohibitive. As such there may be a motivation to include some commercial of the shelf (COTS) PON components in connected access network devices. However, such COTS PON components may lack fail-passive operation design such and possess higher failure rates than more expensive fail-passive components.
As such, it may be desirable to logically and electrically isolate branches of a PON tree from the remaining PON total tree so as to restrict any fault-effect within an isolated branch that branch, avoiding impact on the rest of the PON tree.